1. Technical Field
Example embodiments of the present invention relate in general to human-tracking technologies, and more specifically, to a human-tracking method using an RGB-depth camera and a robot apparatus for performing the same.
2. Related Art
A robot tracking a user based on camera images, which is one method of human-robot interaction, is an important function of a moving robot. The robot tracking the user based on images is a function in which, in a situation where there is no map information about current surroundings, the user may simply walk without a separate device and thereby cause the robot to track.
Such a user-tracking robot system may be created in a variety of methods. A method used in the prior art is a method of tracking legs of a user using a laser range finder (LRF). The LRF outputs omnidirectional depth information parallel to a sensor in a horizontal direction. In the method of tracking legs of the user using the LRF, a position of the legs is estimated from the depth information, and the position is tracked using a particle filter, a Kalman filter, or the like. Another method used in the prior art is a method of detecting a face, an upper body, or a whole body. A robot may detect a face, an upper body, or a whole body from RGB camera images and move in a direction in which a user is located.
Among the methods of the prior art, the method using the LRF has a disadvantage that an LRF sensor is expensive even though it efficiently operates indoors and outdoors. In addition, the method of detecting the face, the upper body, or the whole body has disadvantages that an immediate reaction of the robot is impossible due to a slow detection speed, and detection is likely to fail.